If you are building a bioactive vivarium, you can’t do it without the unsung heroes of the soil: isopods. Often affectionately called "rolly-pollies" or "woodlice," these terrestrial crustaceans are the engine that keeps a bioactive ecosystem running. Without them, you are the janitor. With them, you have a self-cleaning system that manages waste, controls mold, and aerates the substrate.
But not all isopods are created equal. Some prefer bone-dry conditions, while others need a tropical rainforest to thrive. Some breed explosively, making them perfect for feeding hungry reptiles, while others are slow-reproducers better suited for display. In this guide, we will break down the best isopod species for vivariums, so you can choose the right cleanup crew for your specific build.
What Do Isopods Do in a Vivarium?
Before we pick a species, let's recap why you need them. In a bioactive setup, isopods serve three critical functions:
- Waste Breakdown: They eat animal feces, shed skin, and decaying plant matter. They turn this "waste" into smaller particles that bacteria can process.
- Mold Control: Isopods are fungivores. They graze on mold growing on the wood or substrate, keeping the tank clean and your animals safe.
- Soil Aeration: As they burrow through the substrate, they create tunnels. This allows oxygen to reach the roots of your plants and prevents the soil from becoming anaerobic and sour.
The Bioactive Loop
Think of your vivarium as a circle. Your animal creates waste. Isopods eat the waste. Bacteria break down what isopods leave behind. Plants absorb the nutrients released by bacteria. The plants feed your animal (or provide cover). It's a beautiful, closed loop.
Top Isopod Species for Vivariums
1. Porcellio scaber (Rough Woodlouse)
If you are new to isopods, start here. The Porcellio scaber is the quintessential "starter" isopod. They are incredibly hardy, tolerate a wide range of humidity levels, and reproduce quickly. They are usually grey or brown, but "Dalmatian" (spotted) and "Orange" morphs are available for added visual interest.
Best for: General tropical vivariums, beginner setups, and bioactive enclosures for moderate-humidity reptiles.
2. Porcellio laevis (Dairy Cow Isopod)
Larger than the scaber, the Dairy Cow is a bold, fast-moving isopod with a distinct pattern that resembles a cow. They are excellent cleaners because of their size—they can tackle larger chunks of waste that smaller species might ignore. They are also surface-dwellers, meaning you will actually see them walking around, which is part of the fun.
Best for: Larger vivariums, enclosures with bigger reptiles (like Blue Tongue Skinks), and keepers who want visible activity.
3. Armadillidium vulgare (Common Pill Bug)
This is the isopod you likely played with as a child. Known for rolling into a perfect ball when threatened, they are durable and adaptable. While they aren't the most prolific breeders compared to others, they are reliable. They prefer slightly drier conditions than some tropical species, making them great for the "drier" end of a vivarium.
Best for: Arid bioactive setups, mixed-humidity tanks, and outdoor enclosures.
4. Porcellionides pruinosus (Powder Blue/Orange)
Often called "Powder Blues" or "Powder Oranges" depending on the color morph, these are arguably the most prolific breeders in the hobby. If you want your vivarium teeming with life quickly, these are the ones. They thrive in humid, tropical conditions and are voracious eaters of leaf litter and mold.
Best for: High-humidity dart frog vivariums, rapid tank cycling, and serving as a supplemental feeder source.
5. Cubaris sp. "Rubber Ducky"
The "Rubber Ducky" is the celebrity of the isopod world. With their chubby, yellow bodies and dark eyes, they look remarkably like rubber ducks. They are stunning, but they are slow to breed and require stable, high humidity. They are less efficient as cleanup crews simply because their population numbers stay lower, but they are worth keeping just for their beauty.
Best for: Display terrariums, hobbyists who want a challenge, and aesthetic focal points.
6. Trichorhina tomentosa (Dwarf White Isopod)
Tiny, white, and translucent, these isopods are the masters of stealth. They reproduce explosively in humid environments. Because they are so small (about the size of a grain of rice), they are perfect for vivariums housing small animals like thumbnail dart frogs. They burrow deep into the substrate, aerating it from the bottom up.
Best for: Dart frog tanks, small vivariums, and as a primary soil aerator.
How Many Isopods Do You Need?
A common mistake is under-stocking your vivarium. You need enough isopods to establish a breeding population that can outpace the waste production of your animal.
For a standard 10-20 gallon vivarium, we recommend starting with at least 20-30 isopods. If you are using smaller species like Dwarf Whites, start with 50+. It may take 3-6 months for them to establish a colony large enough to be self-sustaining. Until then, you may still need to spot-clean occasionally.
Where to Buy Isopods
You can sometimes find isopods at local pet stores, but the selection is usually limited to common pill bugs. For the specific morphs and species listed above, you will likely need to look online.
- Specialized Breeders: There are many dedicated isopod breeders who ship directly. Look for reviews on reptile forums.
- Reptile Expos: These are great places to buy isopods in person. You can see the health of the culture before you buy.
- Online Communities: Facebook groups and Reddit communities often have "For Sale/Trade" sections where hobbyists sell surplus cultures.
Quarantine Your New Crew
Before adding isopods to your pristine vivarium, keep them in a separate container for a few weeks. This ensures you aren't introducing any unwanted pests, mites, or mold into your main tank.
Isopod Care Basics
Once they are in the tank, they are relatively low-maintenance, but they do have needs:
- Moisture: Provide a moisture gradient. Keep one corner of the substrate damp and the other drier. This allows them to regulate their hydration.
- Calcium: Isopods need calcium to build their exoskeletons. Cuttlebone or crushed oyster shells are excellent supplements to sprinkle on the soil surface.
- Leaf Litter: This is their primary food source. A thick layer of magnolia or oak leaves is essential. Decaying wood is also a favorite.
- Hiding Spots: Use cork bark or pieces of wood to create safe spaces where they can congregate without feeling exposed to light.
Conclusion
Isopods are non-negotiable for a true bioactive vivarium. They do the dirty work so you can enjoy the beauty of your setup. Whether you choose the industrious Porcellio scaber or the stunning Rubber Ducky, adding these crustaceans will bring your enclosure to life in ways you didn't expect.
Start with a hardy species, give them plenty of leaf litter, and watch as they transform your vivarium into a thriving ecosystem.